Known apparatuses for registering accelerations and retardations are burdened with disadvantages, e.g. in the form of a single narrow measuring range, labile neutral position indication, ineffective dampening, especially dampening in the neutral position, while they also lack attitude registering facilities, and have a registering medium feed varying with ambient temperature and/or have registration which is sensitive to temperature.
Registering apparatuses of the type mentioned are customarily utilized for investigating the forces to which goods are subjected during transport. From experience, such forces can be divided into two categories, namely vibrations and shocks. Vibrations of particular interest are those occurring in such situations where goods are transported by a lorry or truck, the vibrations then constituting an indication of the truck springing and road smoothness, and normally have an amplitude of at most about 2 g. Shocks are usually associated with goods handling and can have an amplitude of up to 100 g. Goods are usually packed in such a way that they can withstand minor shocks of up to 10 g, at least when the packed goods have a given prescribed orientation relative to the substructure. Although packing can protect goods against shocks of a given relatively large amplitude, it is not at all certain that the goods will withstand vibrations of relatively low amplitude for a relatively long time, at least in some attitudes.
Apparatuses of the kind in question is normally attached directly to the goods which is to be transported, and should therefore have relatively small physical dimensions these dimensions determining the space for the components in the apparatus. If it is desired to utilize motors, e.g. electric motors, for driving the registering medium, usually a paper web, a problem arises with the batteries of accumulators used for the motor drive, since they have a characteristic which is heavily dependent on temperature. Another disadvantage in connection with registration of measured values is with regard to the type of writing means which is used. For example, if the writing means comprises a stylus which scores a track in a plastic mass on the registering medium, there is always the risk that the stiffness of the mass varies with temperature so that the sensitivity of the apparatus will vary with temperature. This also applies to the cases where the tip of the writing means runs over a pressure-sensitive registering medium which is also sensitive to temperature with respect to effective indication.